javascript - 在 AWS Lambda 中使用 Async/Await 写入 S3 存储桶

Question

我一直在使用下面的代码(我现在已经添加了等待)将文件发送到 S3。它在我的 lambda 代码上运行良好，但当我开始传输更大的文件(如 MP4)时，我觉得我需要异步/等待。

如何将其完全转换为异步/等待？

exports.handler = async (event, context, callback) => {
...
// Copy data to a variable to enable write to S3 Bucket
var result = response.audioContent;
console.log('Result contents ', result);

// Set S3 bucket details and put MP3 file into S3 bucket from tmp
var s3 = new AWS.S3();
await var params = {
Bucket: 'bucketname',
Key: filename + ".txt",
ACL: 'public-read',
Body: result
};

await s3.putObject(params, function (err, result) {
if (err) console.log('TXT file not sent to S3 - FAILED'); // an error occurred
else console.log('TXT file sent to S3 - SUCCESS');    // successful response
context.succeed('TXT file has been sent to S3');
});

Answer 1

您只能await 返回 promise 的函数。 s3.putObject 不返回 promise (类似于大多数接受回调的函数)。它返回一个 Request 对象。如果要使用异步/等待，则需要将 .promise() 方法链接到 s3.putObject 调用的末尾并删除回调(https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/Request.html#promise-property )

try { // You should always catch your errors when using async/await
  const s3Response = await s3.putObject(params).promise();
  callback(null, s3Response);
} catch (e) {
  console.log(e);
  callback(e);
}